Power booster



4 Sheets-Sheet l J. G. HAWLEY BOOSTER Filed April 24. 1941 May 18, 1943 mm. %&

.w M M w May 18, 1943 J, HAWLEY 2,319,231

POWER noosmn Filed April 24, 1941 4 Sheets-Sheet 2 nlsse GuHawle y,

May a Filed April 24, 1941 HAWLEY 2'319231 POWER BOOSTER 4 Sheetsiheet 3 glsse G :9;

y 8,1943 J. G. HA WLE Y' 2,319,23

POWER BOOSTER Filed April 24, 1941 4 Sheen s-Sheet 4.

. the upper power unit, booster,

meme May 18, 1943 UNITED STATES PATENT OFFICE POWER BOOSTER Jesse G. Hawley, Painted Post, N. Y. Application April 24, 1941; Serial No. 390,170

14 Claims. (cuss-1st) This invention relates to the art of power units,

and more particularly to devices for boosting thepower imparted by a hydraulically or mechanically operated device for furnishing motive power.

While many devices have been developed for actuating moving parts, and for boosting power, these have generally been adapted for operating some particular type of mechanism and have lacked general utility as a power unit. Furthermore, such devices have not been capable of achieving the desired step-up in power without involving very complicated construction, and they have also lacked the desired degree of interchangeability for operating various mechanisms.

I have found that it is possible to produce a simple and inexpensive power booster of eneral Fig. 6 in conjunction with the power booster of Fig. 3; and I Fig. 8 is a vertical longitudinal section, corresponding to Fig. 1, showing a modified form of a more particularly to Figs. 1 and 3 thereof, my

utility and'to operate it selectively by hydraulic or mechanical means.

It is therefore an object of this invention toprovide a new and improved power booster.

It is another object to provide a hydraulically operated power booster.

It is a further object to provide a power booster which may be operated either hydraulically or mechanically.

It is an additional object to provide a sealed power unit combined with a power booster. It is also an object to provide a simple and in expensive power unit and power booster of general utility.

It is a special object to provide a power booster for actuating braking devices, I

Withthe above and other objects in view, which will be apparent as the description proceeds, I have set forth my invention in the following specification and have illustrated it in the accompanying drawings, in which:

Figure 1 is a vertical longitudinal section showing my power booster used in connection with airplane wheel brakes; I

Fig. 2 is a vertical transverse section, on an enlarged scale, on the line 22 of Fig. 1, with certain parts removed;

Fig. 3 is a vertical longitudinal section through and brake shown in Figs. 1 and 2;

Fig. 4 is a vertical section on the line 44 of.

Fig. 3; i

Fig.5 is a vertical section on the line 55 of Fig. 3;

Fig. 6 is an end elevation of a mechanically operated means;

Fig. 7 is a vertical longitudinal sectional view of the mechanically operated means shown in power booster III is shown in conjunction with a power unit 20, both of which will be described in detail hereinafter, a brake clamp Ii, provided with brake lining l2, l2", and a braking disc II. The latter is preferably a circular disc that is screwed or riveted, as at II, to the'outer end l4 of awheel hub ii. v

The preferred operating mechanism for use in conjunction with my power booster is a power unit", which is preferably of the type disclosed and claimed in my co-pending applications, Se-

rial No. 337,102, filed May 24, 1940, and Serial No.

355,263, flled September 3, 1940. This preferably comprises a fluid cylinder 2 I ,a piston cylinder 22, a resilient seal 23, a piston 24, and a piston rod 24.

As best shown in Fig. 3, fluid cylinder 2land piston cylinder 22 are cup-shaped members terminating in circumferential flanges 28 and 21,

to oils. It is made of any suitable material, such.

as neoprene, bunairubber, or thiokol. As shown.

it comprises a bottom portion 32 which is flat,

side wall 33 at right angles thereto, and the aforementioned flang 28 which extends at right angles to' the side wall 33 and terminates in a secondary flange 34 that is parallel to the side wall 33 but spaced therefrom.

The piston 24 comprises a head 35 anda circumferential flange 36 at right angles thereto. I

Piston cylinder 22 comprises a bottom portion 21, which is flat but is provided with an orifice 28, for a purpose to be described later, and a side wall 40, whose internal diameter is equal to the internal diameter of the side wall 23 of resilient seal 23, and which is only sufliciently larger than the external diameter of the flange 36 on piston 24 to permit it to move freely therethrough. Side wall 40 terminates in the flange 21 described above, and this, in turn, is provided with a right angular extension 4I,'which is parallel to the side wall 40 and of a. suitable internal diameter such that it just accommodates spacer ring 38 and flange 34 of resilient seal 23.

Fluid cylinder 2I comprises a bottom portion 42 provided with a side wall 43 that is of just sufficient internal diameter to allow the side wall 33 of resilient seal 23 to fit therein without deformation. Side wall 43 terminates in flange 26 discussed above.

Bottom portion 42 is provided with two bosses 50, 54 hat are preferably formed integral therewith. Boss 58 is internally threaded at 5i to receive any suitable coupling (not shown), andis provided with an orifice 52 to permit fluid (not shown) to enter a chamber 53 formed in fluid cylinder 2I between its bottom portion 42 and the resilient seal 23. Boss 54 is preferably internally threaded to receive a correspondingly threaded bleeder plug 55, provided with a square head 58. Bleeder plug 55 communicates with the exterior through a longitudinal orifice (not shown) that communicates with a transverse oriflce 51, in a shank 58 of reduced diameter. Orifree 51 can communicate with a transverse oriflce 68 in bottom portion 42 of fluid cylinder 2|, and thence with the chamber 53 when the bleeder plug 55 is partially unscrewed from its seat 6I.

This may conveniently be done with a screw driver by inserting the latter in a transverse slot 62 in the head of the bleeder plug 55.

Piston rod 25 is provided with aflat head 10 and a tapered end 1 I. Piston rod 25 operates in.

u and is guided by, a power head 16 that has a longitudinal aperture 11 of just sufficiently larger internal diameter than piston rod 25 to allow the latter to move therein without undue friction. Power head 16 is preferably a screw machine part that is externally threaded at 18.

The travel of piston rod 25 is preferably controlled by a spacer 84, provided with an external flange 85, whose external diameter corresponds to the internal diameter of the side wall 40 of piston cylinder 22, and with an orifice 86 that is of large enough diameter to permit the piston rod 25 to move therethrough without undue friction. A spacer sleeve 81, that is of sufficiently smaller external diameter to fit snugly in spacer 84, and of larger internal diameter than the oriflce 86, is designed to retain a stop pin 88, carried by the piston rod 25 but projecting therebeyond, so as to limit the travel of the piston rod 25 between the spacer 84 and the inner end of power head 16. Spacer sleeve 81 is preferably separate from the threaded portion 18 of power head 16. Spacer 84 is also internally threaded to engage the inner threaded end 18 of power head 16.

A heavy coil spring 90 is telescoped around spacer 84, and bears against the flange 85 thereof and against the head 18 of pistonirod 25, to normally force the latter into engagement with piston 24 and cause that to bear against resilient My power booster I8 comprises a housing 9| which is internally threaded at 92 to engage the threaded portion 18 of the power head 16. Housing 9I is also provided with an enlarged recess '93 which is connected with the internally threaded portion by an inclined face 94. The outer end of the power head 16 is also enlarged at 95 and provided with a correspondingly inclined portion 96, for cooperation with the inclined face 94 of 'the housing-9|, and a flat operating face 96' Housing 9I is also provided with a separate concave-faced pressure 'disc 91'. Three ball bearings 98 are interposed between the flat face 96 of the outer end of powerhcad 16 and the concave-faced pressure disc 91 and are actuated as described later. The pressure disc 91 is springpressed toward the enlarged end 95 of power head 16 through a plurality of retaining rods I which are housed in longitudinal recesses 99 in the inner periphery of housing 8|. Retaining rods I00 each terminate in a portion IOI disposed at right angles thereto for reception in a recess I02 in the pressure disc 91. At their opposite ends, the retaining rods I00 are headed at I03, and a coil spring I04 is provided for each of the retaining rods I00 and is adapted to bear against the head I03, and a seat. I formed in the periphery of the housing 9I. This spring mechanism is protected by a-dust cap I06 which is adapted to seat in a recess I01 on the outer end of the housing SI, and bear against a flange I88 integral with the housing 9|. Flange I08 is recessed on its'under side I09 to lighten it. Lock nuts IIO, III are provided on the power head 16 to retain the power unit 28- and dust cap I86, respectively, in the desired positions thereon.

The brake clamp II is secured to the housing 9| by bolts I I2 and nuts H3 which pass through the flange I08 on the housing 9| and the brake clamp II,-and are provided with springs II4 telescoped around'these bolts to give the brake clamps a slight yielding movement during the braking action.

With the construction described, when it is desired to actuate the power booster, the operator supplies actuating fluid to the power unit 20 by moving a lever orpressing a button (not shown) which causes fluid from any suitable outside source (not shown) to enter chamber 53 in fluid cylinderZI, through the orifice and bear against the exposed portion '32 of re'silientseal 23. This moves piston 24 and piston rod 25 for ward against the pressure of spring 98 and forces the tapered endll of pistonrod 25 outwardly into contact with the ball bearings'98 to 'force these into contact with the concave-faced pressure disc 91. As the tapered end H is forced outwardly, the ball bearings. are caused to ride'up the inclined portion of the face of the pressure disc, which resists the spreading of the ball bearings, and exert a stepped-up pressure against the pressure disc and any parts in its path of travel. As the pressure disc 91 is forced outwardly, springs I04 are compressed to provide the means for withdrawing the pressure disc from the parts which it actuates when the tapered end H is subsequently withdrawn.

By varying the taper of theend II of piston rod 25 and the angle of inclination of the concave-faced pressure disc 91, any desired degree the concave-faced pressure disc 91 is 30. Consequently, if the piston rod 25 is movediorward /4 inch, the pressure disc 91 only moves forward 1 3 inch, so that if '1-,000 poundsis exerted against the piston rod 25, 4,000 pounds pressure will be delivered by the'pressure disc 91.

In the embodiment shown in the drawings, the pressure exerted by the pressure disc 91 is exerted against the innermost brake lining I2, thus forcing the latter into contact with the braking disc I3. This action simultaneously pulls 'the outer brake lining I2, carried by the outer portion of the brake clamp I I, into contact with the opposite side of the braking disc I3 to complete the brake application.

The brake-clamps II are cut away at their lower side to provide an entrance slot II5 to accommodate the brake disc I3, and with a recessed portion I I6 to receive the brake lining I2.

As shown in Fig. 1, the axle I8 is supported in the wheel hub I5 by a pair of Timken bearings I20, each of which is retained in position by a washer assembly comprising a felt washer I2I protected by metal washers I22 and [23 and a spring retaining ring I24 which is received in a recess I25 in the wheel hub I5.

At its outer end, axle I8 is provided with threads I26 to .receivea retaining nut I21.

A tire I30 is mounted on the wheelhub I5 and is retained thereon between flange I3I on the inner side of th'e'hub and a retaining flange I32 on the outer side of the'hu'b. The latter is retained in position by aspring retaining ring I33 which is received in registering recesses I34 and I35 in the wheel hub I5- and retaining flange I32,

respectively.

A light metal hubcap I36 is bolted to, or spring held in, the retaining flange I32 to prevent the entrance of dirt and moisture.

The braking disc I3, which is mounted externally of the wheel hub in Fig. 1, may be replaced by a braking disc that is mounted internally.

As shown in Fig. 8, a braking disc I40 isscrewed or riveted at I4'I to the outer end I42 of a wheel hub I43. 1

Inthis modification, the power units" and the power boosters I0 are preferably the same as disclosed in conjunction with Figs. 1 and 3, except-that the shape of the flange I08 of hous- .ing 9|, of brake clamp ligand of the springpressed bolt construction for retainingthese. parts in the desired relationship, are changed as indicated below. Although omitted from Fig. 8, for the sake of clarity, retaining rods I00, coil springs I04, and dust cap I116 are provided in the same way as in Fig. 3.

As shown in Fig. 8, the wheel hub I43 is prefer-- ably formed in-two parts I44, I45 which are retained in assembled position by bolts I46 and nuts I41. The positioning of parts I44, I45 is preferably facilitated by providing them with co-' operating lugs I48 and recesses I50.

An axle I5I is supported in the wheel hub I43 by a pair of Timken bearings I52, I53, which are I retained in position by a pair of sleeves I54, I55 having flanges I56, I51, respectively, for contact with the bearings I52, I53. Axle I5I is threaded at I58 to receive a retaining nut I60, which is drawn up tight against the flange I51-of sleeve I55 to hold the parts in assembled position.

I Brake clamps I6I cooperate with flanges I62 on the housing 0I'. through the aid of bolts I63 and nuts I64, the bolts I63'passing through registering orifices I65, I66 in the brake clamps I6! and flanges 5-62. bolts hold in position hich are provided *ively, that engage The flanges other and to a retwo spacing collars It'l. I68 with flanges I10, Iii, respethe periphery of spacin sit I10, Ill are secured to one a taining ring .523 by bolts lit and nuts lid.

position in any desired way, as by cotter pins I83.

The construction just described results in the secure anchoring of the spacing collars I61 ,IGB. More than a limited movement away from the hub I43 is prevented by the contact of clamps I-6I and brake lining I2 against the braking disc I40. Movement oi,the spacing collars I61, I63 toward hub I43 is prevented by the contact of circular plate I12 against the end of sleeve I54, whose further movement is prevented by the contact of flange I56 against bearing I52. The flange I51 of sleeve I55 bears against bearing I53 in a similar manner.

As shown in 'Fig. 8, the brake lining I2 is resolved in a .recessed portion I84 of brake clamp I6I. Also, the housing SI of my power booster overlies the end I42 of the hub I43.

A dust cover I85 is provided for the outer end of hub I43 and may be secured thereto in any desired manner, as by the screws 66.

In the embodiment shown in Fig. 8. when the power unit 20 is actuated and the tapered end- 'II of piston rod 25 bears against the ball bearings '98 to cause them to ride on the inclined face of pressure disc 91, brake lining I2 is forced against braking disc I40, and this. in turn, through the spring-pressed construction previously described, pulls the brake lining I2, carried by brake clamp I6'I, into contact with the opposite side of the braking disc I40. When the piston rod 25 is withdrawn under the influence of spring 90, the spring mechanism described above. releases the pressure of brake lining I2 against braking disc I40, allowing the latter to turn freely between the brake linings I2 and I2.

may be operated mechanically through the aid of a lever I81, which is preferably pivotally mounted at I88 between a pair of :lugs I89 projecting from a sleeve I60. The latter is threaded onto-the threaded portion'18 of power head 16 and is held in the desired adjustment by lock nut IIO. In this modification. the parts of the power booster correspond to that shown and described in connection with Fig. 3.

'When it is desired to operate the power booster mechanically, it is merely necessary to pull outwardly on the end of the operating lever I61. which. will rock it on its pivot I88 so it will bear against the outer end I9! of an operating plunger 25' to force its tapered end III into contact with the ball bearings 98"and cause them t ride upwardly on pressure disc 91. The outer end ol lever I81 may be connected to any desired lever or pull cord (not shown).

The parts of my brake construction and related mechanism may be made of any desired materials. In general, however, I prefer to make the braking disc of chromium plated carbonsteel or stainless steel. For airplane use, the wheel hub ispreferably of light weight material, such as aluminum or magnesium alloys of the Dow Metal type. The

' clamp is also preferably made of Dow Metal or power boosters, power units, and related brake mechanisms in Figs. 1, 2, and '8, it will be understood that I may use one or any desired number of these power unit clamp brakes. Furthermore,

I .these power units may be varied in diameter, and the amount of the operating fluid supplied to them may be varied, and all of these conditions will vary the amount of braking pressure. Also,

by a proper distribution of the power unit brakes around the periphery of the circular disc, a substantially equal pressure may be exerted around its entire: periphery, and, by the use of proper springs ill, the braking thrust can beproperly balanced} Also, in; view ofthe simple construction of the parts shown, any broken or damaged unit may easily be replaced and a new unit substituted without disassembling the wheel orthe tire.

Although invention has been disclosed herein in connection with a new and useful brake which is capable of general application, but which is particuhrly adapted for airplane use, it will beunderstood that the presentinvention is primarily directed to my improved booster. In

' 1 viewjhowever, of the new-and improved result obtained by using mynew power unit and power booster to form a new and useful brake assembly,

- it will also be claimed in conjunction with the brake elements. I

Inaddition to its usefulness in conjunction with brakes, my improved booster may be used for many other purposes. Without-in any way limiting myself thereto, it may be stated that it is useful in presses, such as-arbor presses and' punch presses, or for exerting a sustainedpressure, as when cementing bands of sandpaper or emery paper. In many of these uses, it makes possible the development of the desired pressure in a small press instead of requiring the use of a big'press; in other cases, it results in the production of a greater pressure than could be withstood by the normal press elements without stripping the teeth from the pinion gear or gear rack if the desired pressure were applied directly to them. It is a particular point of my improved power booster that the pressure desired is obtained in a straight line push.

It will therefore be apparent that I have developed a simple and efficient means of boosting the power'applied by a given source of power and that by varying the angle of the tapered end of the piston rod or of thefoperating plunger,

" as well as the'angle of the face of the pressure disc, I am able to obtain a-marked increase in actuating rod and the face of the pressure disc, and a powerhead surrounding the actuating rod and preventing movement of the ball'bearings in other than a lateral direction, whereby, upon the movement of the actuating rod, its tapered end will force the ball bearings apart against the resistance oil'ered by the pressure disc and deliver a greater pressure against the face of the pressure disc than would be delivered were the actuating rod to bear directly thereagainst.

2. A power booster, comprising a housing, a pressure disc therein provided with an inwardly tapering face, a plurality of ball bearings arranged thereagainst, and a tapered actuating means arranged at a point equidistant from the centers of the ball bearings and adapted, when pressed against the ball-bearings, to cause the latter to separate and ride up the tapering" face of the pressure disc.

3. The pressure disc of claim 2, in which means are provided for guiding the tapered member and for resiliently forcing said pressure disc against the ball bearings and causing the latter to bear against the endof said guide means.

4. A power booster, comprising a 2-part housing, a pressure disc disposed therein and provided with an inwardly tapering face, a tapered actuating means, a guide therefor, a plurality of ball bearings disposed between said guide and said pressure disc with the end of the actuating means arranged equidistantly from the centers of the ball bearings, spring-pressed retaining rods holding the pressure disc in contact with'the ball bearings, a dust cap for the housing and retaining rods, and a resilient means for yieldingly holding the parts of the housing in contact.

5, A power unit assembly, comprising a concave-faced pressure disc, a taperedplunger, means for actuating said tapered plunger, and a ball bearing power transmitting means arranged between the tapered plunger and the pressure disc, said assembly being adapted when the plunger is pressed against the ball bearing means to cause the latter to separate and ride up the concave-faced pressure disc.

" 6. The power unit assembly of claim 5, in which the power is supplied by a pneumatically operated power unit.

' '7. The power unit assembly of claim 5, in which the power is supplied by a mechanically opera-ted power unit. I

' 8. The power unit assembly of claim 5, in which the power is supplied by a mechanically operated lever, one end of which presses against the opthe power delivered by the-power'unit, and tha this may be varied over wide limits. I As many apparently widely different'embodiments of this invention may be made without I provided with a tapered actuating rod, a concave-faced pressure disc, a plurality of ball bear- 'ings interposed between the tapered end of the 1g posite, end of the tapered plunger. I f 9.'A brake mechanism, comprising. a wheel hub, a braking disc carried thereby, a doublejawed brake disposed on opposite sides of the braking disc, brake lining disposed in said jaws and on opposite sides of the braking disc, springcontrolled means for yieldingly holding said brake jaws together, a power booster provided with a pressure disc which has an inwardly tapering face, a plurality of ball hearings in contact with said tapering face, a pointed plunger arranged at a point equidistant from the centers of the ball bearings, andactuating means for forcing said plunger into contact with the ball hearings to spread them apart and cause them to ride up the tapering face of the pressure disc and force the latter into contact with the brak lining to apply the brake. 10. The brake mechanism of claim 9, in which the braking disc is arranged externally of the wheel hub.

ama eur p 5-,

11. The brake mechanism of claim 9, in which the braking disc is arranged internally of the wheel hub.

12. A brake mechanism. comprising a wheel hum braking disc mounted circumferentially thereon, a plurality of open-jawed power booster brakes arranged at intervals around said braking disc, and means for actuating said powerboosters, each of said power boosters comprising a concave-faced pressure disc. 9. pointed aeti'iat- 10 int means, a plurality of ball bearings disposed between said pointed actuating means and said pressure disc, and means for retaining said ball bearings thereagainst.

13. The brake mechanism of claim 12, in which the braking disc is arranged externally of thewheel hub.

14. The brake mechanism of claim 12, in which the braking disc is arranged internally of the wheel hub.

JESSE G. HAWLEY. 

